In the industry flexible conductive adhesive having a low modulus of elasticity is applied as conductive bumps on the contact pads of the substrate or on the contact pads of the semiconductor chips. Many types of adhesives, fillers, resins and conductive particles are used for making the substrate for a flexible adhesive membrane to be used in semiconductor chips, resistors, capacitors etc. and the process of making these layers take an enormous amount of time, money and steps. The adhesive joints are local and do not span the entire length and breadth of the material they are used on.
An electronic device includes electronic components, such as “flip chip” semiconductor devices, chip resistors, capacitors and other electronic components, mounted and interconnected to a substrate by a flexible adhesive membrane having contact pads that have substantially the same pattern as those of the corresponding electronic components [3]. The flexible adhesive membrane includes an insulating matrix and conductive pads therein that employ thermoplastic and thermosetting adhesives, and combinations thereof, each having a low modulus of elasticity. A low stress conductive material or paste adhesive that comprises a) one or more functional acrylic copolymers or terpolymers; b) epoxy; and c) conductive filler was described [4]. A sealed-by-resin type semiconductor device includes a substrate, a lead provided on the substrate, and a semiconductor element provided on the lead by flip chip bonding was described [5]. Several different types of electrically conductive elastomers are disclosed along with the methods for their fabrication: in one particular embodiment, a layered composition is disclosed which comprises a substrate, a first layer, and a second layer, the substrate is formed of a non-conductive elastic material and it has an outer surface [6]. A quantity of rounded or jagged conductive particles may be imbedded in an outer surface of the second layer.
An electronic device includes electronic components, such as “flip chip” semiconductor devices, chip resistors, capacitors and other electronic components, mounted to and interconnected to a substrate by a flexible adhesive membrane having contact pads that have substantially the same pattern as those of the corresponding electronic components [7]. Thermal transfer between a semiconductor wafer and a platen during vacuum processing is provided through a soft, thermally-conductive polymer layer having a thin, hard surface conductive material [8]. The soft polymer layer, which is preferably silicon rubber containing thermally-conductive particles, conforms to surface irregularities on the wafer and has low thermal resistance.
The flexible elastic conductive materials can be used for strain sensor applications [9,10]. A strain sensor is a device that converts the changes in the length (Δl) of the sensor or object into change in the resistance (ΔR) in the sensor. Strain (S) is ratio of Δl to length (l) [9,10]:S=Δl/l  [1]Sensitivity of sensor or gauge factor (G) is:G=ΔR/RS  [2]
The strain sensitivities of some sensors that are used in practice, for example, for constantan and silicon are equal to 2.1 and 120, respectively [9,10]. The materials and strain sensors sensitivities are presented in order to bring some examples of the materials and devices which are used at present in practice. There is a need for a better fabrication method of the conductive material that is cheap and easy to fabricate.